GG,
Sorry not sure about # 1
Regarding # 2, since you have a CDR-220 you can order a part from Becker that plugs into the back of your radio and then connects directly to the audio input of your satellite receiver just like an Ipod :
http://www.beckerautosound.com/Porsche/99_01_carrera_cdr220_cd_4462.html
The plug from Becker plugs into the back of the radio with RCA inputs on the other end. You will need a cable to go from the RCA to the satellite receiver.
You might want to try these guys for a mounting solution :
http://www.proclipusa.com/home/home.aspx
I have satellite radio in the house and on my bike, but I cannot figure a decent way to mount it in the Boxster so I just use my Ipod in the car.
Hope this helps…
Nick